#include "md5.h"

#include <stdio.h>
#include <time.h>
#include <string.h>

#pragma warning(disable:4996)

/* MD5 initialization. Begins an MD5 operation, writing a new context.
*/
void MD5Init(MD5_CTX *context)
/* context */
{
	context->count[0] = context->count[1] = 0;
	/* Load magic initialization constants.
	*/
	context->state[0] = 0x67452301;
	context->state[1] = 0xefcdab89;
	context->state[2] = 0x98badcfe;
	context->state[3] = 0x10325476;
}

/* MD5 block update operation. Continues an MD5 message-digest
operation, processing another message block, and updating the
context.
*/

void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputLen)
/* context */
/* input block */
/* length of input block */
{
	unsigned int i, index, partLen;

	/* Compute number of bytes mod 64 */
	index = (unsigned int) ((context->count[0] >> 3) & 0x3F);

	/* Update number of bits */
	if ((context->count[0] += ((UINT4) inputLen << 3))
		< ((UINT4) inputLen << 3))
		context->count[1]++;
	context->count[1] += ((UINT4) inputLen >> 29);

	partLen = 64 - index;

	/* Transform as many times as possible.
	*/
	if (inputLen >= partLen)
	{
		MD5_memcpy((POINTER) & context->buffer[index], (POINTER) input,
			partLen);
		MD5Transform(context->state, context->buffer);

		for (i = partLen; i + 63 < inputLen; i += 64)
			MD5Transform(context->state, &input[i]);

		index = 0;
	}
	else
		i = 0;

	/* Buffer remaining input */
	MD5_memcpy((POINTER) & context->buffer[index], (POINTER) & input[i],
		inputLen - i);
}

/* MD5 finalization. Ends an MD5 message-digest operation, writing the
the message digest and zeroizing the context.
*/
void MD5Final(unsigned char digest[16], MD5_CTX *context)
/* message digest */
/* context */
{
	unsigned char bits[8];
	unsigned int index, padLen;

	/* Save number of bits */
	Encode(bits, context->count, 8);

	/* Pad out to 56 mod 64.
	*/
	index = (unsigned int) ((context->count[0] >> 3) & 0x3f);
	padLen = (index < 56) ? (56 - index) : (120 - index);
	MD5Update(context, (unsigned char*) PADDING, padLen);

	/* Append length (before padding) */
	MD5Update(context, bits, 8);
	/* Store state in digest */
	Encode(digest, context->state, 16);

	/* Zeroize sensitive information.
	*/
	MD5_memset((POINTER) context, 0, sizeof(*context));
}

/* MD5 basic transformation. Transforms state based on block.
*/
static void MD5Transform(UINT4 state[4], unsigned char block[64])

{
	int i = 0;

	UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];

	Decode(x, block, 64);

	/* Round 1 */
	FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
	FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
	FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
	FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
	FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
	FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
	FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
	FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
	FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
	FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
	FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
	FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
	FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
	FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
	FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
	FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

	/* Round 2 */
	GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
	GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
	GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
	GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
	GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
	GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */
	GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
	GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
	GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
	GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
	GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
	GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
	GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
	GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
	GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
	GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

	/* Round 3 */
	HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
	HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
	HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
	HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
	HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
	HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
	HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
	HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
	HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
	HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
	HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
	HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */
	HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
	HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
	HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
	HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */

	/* Round 4 */
	II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
	II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
	II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
	II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
	II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
	II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
	II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
	II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
	II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
	II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
	II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
	II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
	II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
	II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
	II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
	II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */

	state[0] += a;
	state[1] += b;
	state[2] += c;
	state[3] += d;

	/* Zeroize sensitive information.
	*/
	MD5_memset((POINTER) x, 0, sizeof(x));
}

/* Encodes input (UINT4) into output (unsigned char). Assumes len is
a multiple of 4.
*/
static void Encode(unsigned char *output, UINT4 *input, unsigned int len)

{
	unsigned int i, j;

	for (i = 0, j = 0; j < len; i++, j += 4)
	{
		output[j] = (unsigned char) (input[i] & 0xff);
		output[j + 1] = (unsigned char) ((input[i] >> 8) & 0xff);
		output[j + 2] = (unsigned char) ((input[i] >> 16) & 0xff);
		output[j + 3] = (unsigned char) ((input[i] >> 24) & 0xff);
	}
}

/* Decodes input (unsigned char) into output (UINT4). Assumes len is
a multiple of 4.
*/
static void Decode(UINT4 *output, unsigned char *input, unsigned int len)

{
	unsigned int i, j;

	for (i = 0, j = 0; j < len; i++, j += 4)
		output[i] = ((UINT4) input[j]) | (((UINT4) input[j + 1]) << 8)
		| (((UINT4) input[j + 2]) << 16)
		| (((UINT4) input[j + 3]) << 24);
}

/* Note: Replace "for loop" with standard memcpy if possible.
*/

static void MD5_memcpy(POINTER output, POINTER input, unsigned int len)

{
	unsigned int i;

	for (i = 0; i < len; i++)
		output[i] = input[i];
}

/* Note: Replace "for loop" with standard memset if possible.
*/
static void MD5_memset(POINTER output, int value, unsigned int len)

{
	unsigned int i;

	for (i = 0; i < len; i++)
		((char *) output)[i] = (char) value;
}

/* Digests a string and prints the result.
*/
char* MDString(char *string)
{
	MD5_CTX context;
	unsigned char digest[16];
	char output1[128];
	static char output[33] =
	{ "" };
	unsigned int len = strlen(string);
	int i;
	MD5Init(&context);
	MD5Update(&context, (unsigned char*) string, len);
	MD5Final(digest, &context);

	for (i = 0; i < 16; i++)
	{
		sprintf(&(output1[2 * i]), "%02x", (unsigned char) digest[i]);
		sprintf(&(output1[2 * i + 1]), "%02x",
			(unsigned char) (digest[i] << 4));
	}
	for (i = 0; i < 32; i++)
		output[i] = output1[i];
	return output;
}

/* Digests a file and prints the result.
*/
char* MDFile(char *filename) {
	static char output[33] =
	{ "" };
	FILE *file;
	MD5_CTX context;
	int len;
	unsigned char buffer[1024], digest[16];
	int i;
	char output1[128];
	if ((file = fopen(filename, "rb")) == NULL)
	{
		printf("%s can't be openedn", filename);
		return 0;
	}
	else
	{
		MD5Init(&context);
		while (len = fread(buffer, 1, 1024, file))
			MD5Update(&context, buffer, len);
		MD5Final(digest, &context);
		fclose(file);
		for (i = 0; i < 16; i++)
		{
			sprintf(&(output1[2 * i]), "%02x", (unsigned char) digest[i]);
			sprintf(&(output1[2 * i + 1]), "%02x",
				(unsigned char) (digest[i] << 4));
		}
		for (i = 0; i < 32; i++)
			output[i] = output1[i];
		return output;
	}
}

char* hmac_md5(char* text, char* key)
{
	char digest[16];
	char output1[256];
	static char output[33] =
	{ "" };
	MD5_CTX context;
	unsigned char k_ipad[65]; /* inner padding -
							  * key XORd with ipad
							  */
	unsigned char k_opad[65]; /* outer padding -
							  * key XORd with opad
							  */
	unsigned char tk[16];
	int i;
	int text_len = strlen(text);
	int key_len = strlen(key);
	/* if key is longer than 64 bytes reset it to key=MD5(key) */
	if (key_len > 64)
	{

		MD5_CTX tctx;

		MD5Init(&tctx);
		MD5Update(&tctx, (unsigned char*) key, key_len);
		MD5Final(tk, &tctx);

		key = (char*) tk;
		key_len = 16;
	}

	/*
	* the HMAC_MD5 transform looks like:
	*
	* MD5(K XOR opad, MD5(K XOR ipad, text))
	*
	* where K is an n byte key
	* ipad is the byte 0x36 repeated 64 times
	* opad is the byte 0x5c repeated 64 times
	* and text is the data being protected
	*/

	/* start out by storing key in pads */

	/*bzero( k_ipad, sizeof k_ipad);
	bzero( k_opad, sizeof k_opad);
	*/

	for (i = 0; i < 65; i++)
		k_ipad[i] = (unsigned char) 0;
	for (i = 0; i < 65; i++)
		k_opad[i] = (unsigned char) 0;

	/*bcopy( key, k_ipad, key_len);
	bcopy( key, k_opad, key_len);
	*/
	for (i = 0; i < key_len; i++)
	{
		k_ipad[i] = (unsigned char) key[i];
		k_opad[i] = (unsigned char) key[i];
	}

	/* XOR key with ipad and opad values */
	for (i = 0; i < 64; i++)
	{
		k_ipad[i] ^= 0x36;
		k_opad[i] ^= 0x5c;
	}
	/*
	* perform inner MD5
	*/
	MD5Init(&context); /* init context for 1st
					   * pass */
	MD5Update(&context, k_ipad, 64); /* start with inner pad */
	MD5Update(&context, (unsigned char*) text, text_len); /* then text of datagram

														  */
	MD5Final((unsigned char*) digest, &context); /* finish up 1st pass */
	/*
	* perform outer MD5
	*/
	MD5Init(&context); /* init context for 2nd
					   * pass */
	MD5Update(&context, k_opad, 64); /* start with outer pad */
	MD5Update(&context, (unsigned char*) digest, 16); /* then results of 1st
													  * hash */
	MD5Final((unsigned char*) digest, &context); /* finish up 2nd pass */
	for (i = 0; i < 16; i++)
	{
		sprintf(&(output1[2 * i]), "%02x", (unsigned char) digest[i]);
		sprintf(&(output1[2 * i + 1]), "%02x",
			(unsigned char) (digest[i] << 4));
	}
	for (i = 0; i < 32; i++)
		output[i] = output1[i];
	return output;
}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

